1. Field of the Invention
This invention relates generally to a self-travelling vibration generator, and more particularly to a self-travelling vibration generator wherein eccentric rollers give vibration to the abdominal region of a patient lying on his face on a bed, while travelling on the abdominal surface.
2. Description of the Prior Art
Self-travelling vibration generators for giving vibration to the back region of a patient lying on his back on a bed while travelling along the back surface are already known. On the contrary, the present applicant has proposed earlier a self-travelling vibration generator wherein the vibrating element thereof gives vibration to the abdominal region of a patient lying on his face, not on his back, on a bed while travelling along the abdominal surface.
In such a device, however, eccentric rollers as the vibrating element tend to sink into the abdominal surface because the abdominal surface is relatively soft and flexible. It was found that this necessitates a relatively large power for motors for causing the eccentric rollers to travel and vibrate.